If You’re Not Using Python DATA CLASSES Yet, You Should 🚀

[@ArjanCodes]

Anybody else into The Witcher?

[@Newascap]

If you talking about the game, I bought it on gog but never got the chance to install it. Too much time fighting with k8s manifests and no time for playing :c

[@ArjanCodes]

I have the Witcher 3 for the Playstation lying in a drawer, haven't gotten around to that either.

[@draufunddran]

@@ArjanCodes I have the Witcher 3 also lying in a drawer but mine is for the xbox :D

[@leftblank5315]

I thought the show had a bit of corny dialog but the more i watched it the more i was immersed and it didn't seem bad. so yeah i love it

[@itsmemouha2811]

You've got to read the books, a masterpiece. If you liked the TV show or didn't, it won't matter after reading just the first two short story collection.

[@falak88]

Just in case you're feeling low Arjan, you are doing a freaking great job here. Thank you very much ! Keep them coming :D

[@ArjanCodes]

Thank you so much for your kindness, much appreciated! I’m happy you like the videos.

[@myhome...essenceofmylife5612]

2222²²²awaŕd

[@drymanic]

One cool thing about the "frozen" attribute is that if set to True, Python will automatically create a ___hash___ function for your dataclass, allowing it to be used in things like dictionary keys and sets. (Note that if the class contains an unhashable field such as a list, the ___hash___ function will throw an exception).

[@JohnMitchellCalif]

Incredibly clear presentation. I've been programming Python for 25 years and hadn't used data classes. Thanks! Subscribed.

[@jakefischer8281]

I believe it is fairly new to python

[@dennissmith6867]

This is a really great intro to data classes, very clear and to the point. Looking forward to more videos like this!

[@ArjanCodes]

Glad you liked it, Dennis!

[@CodingEntrepreneurs]

This is great! Thanks for sharing Arjan. Love your work.

[@jayeshdeorukhkar4956]

Love your videos too 🔥

[@skyletwings5711]

8:43 "So frozen helps you to make sure the data is not changed anywhere in your code." ... right after bypassing this mechanism and showing how the data is changed in the code. :D Great videos, you are my no. 1 python instructor. Programming python itself is fun, but learning from a patient, calm, well explaining teacher is invaluable, but free. Thank you for sharing!!

[@alicebrown854]

Where is 'love' button? 'Like' is not an accurate reflection of what I feel about your videos. I've seen many amazing dudes with online tutorials on KZbin, but you are the most amazing

[@myce-liam]

Arjan, your videos are really clear and simple. You are very much appreciated. Greetings from the UK!

[@ArjanCodes]

Thanks so much Liam, glad the content is helpful!

[@jimmy21584]

When dealing with data in Python these days, I find myself almost exclusively doing comprehensions and functional programming with dictionaries and lists, rather than using classes. But good to know this is out there.

[@ZergD]

I concur with that!

[@AddyVDH]

This is the best way IMO. Heavy OOP often makes python code super messy as many people get involved in a codebase.

[@bakane6030]

@@AddyVDH Agreed. Python is NOT supposed to be an object oriented language

[@nsambataufeeq1748]

I had a graduate class in LISP, i found the functional bits interesting and are now using them in python

[@JustMaiyak]

FP un Python feels great !

[@mithunmanoharmithun]

I would love to see a complete python course taught by Arjan!

[@typehint]

Really happy I found your channel! You and Corey Schafer are my two favourites for learning Python right now. Keep up the excellent work!

[@ArjanCodes]

Thanks so much Finah.

[@Bc7-w9k]

I LOVE U, THIS IS THE FIRST STEP FOR UNDERSTAND FAST API AND PYDANTIC, THANK U FOR URS VIDEOS

[@kyletech4878]

I find the asdict and astuple methods from the dataclass library very handy.

[@DanielRios549]

This is something I was wondering to use in Python since I discovered that in PHP 8, you do not need to set the construct parameter to attributes anymore, you set the attributes directly on the parameter, this is very useful when you have a lot of initial parameters, pass the parameter and after that set it to an attribute is so so boring

[@Yassou1985]

Arjan keep doing your video man ! Your are a true teacher, everthing you say is just so clear. Thank you for your help :)

[@ArjanCodes]

I'm glad my content has been helpful! Thank you for the kind words :)

[@cetilly]

Awesome! Coming from a C# background this really makes my day to know data classes are a thing in Python. Awesome. Really good video. Thanks Now I need to refactor all my custom data classes :-D

[@ArjanCodes]

It seems technical debt never really stops 😊.

[@theophilegaudin2329]

I started using classes when I could not do otherwise. My fonctions had like 15 variables that I had to state explicitly. It was impractical. My code was working on molecules and mixtures of molecules. So I created a class "mixture" and a class "molecule" and suddenly my fonctions were acting on mixtures and molecules rather than long lists of variables. That was such a relief. Now my classes have like 70 attributes because, well, mixtures and molecules have many structural features and properties. Everytime I extend my code I simply add new attributes and that's it.

[@nlight8769]

I've been coding for... hmm... since python 2.5 as an amateur, when I need it. The vast majority of what I learned is from back then, and while i've been keeping learning, in the last years, besides some modules here and there, I've not learned many new things... discovered the chanel last week, and man I've learned so much since ! Sure there are few design pattern that I was already doing out of pure logic and commodity, though even then the knowledge acquired here have allowed me to refine these to the next level (or on the road to it), plus the terms that goes with it ! Thank you so much ! And there are many new neat things that I've been missing, like the module abstractclass or this dataclass. A great channel : advanced and intermediate concepts, in python !

[@ArjanCodes]

Thank you, I'm happy you like the content!

[@Egon3k]

Everytime watching one of your videos, I learn something new. Keep on going with these very nice and easy to understand videos :)

[@aar021]

That intro was hilarious. Well put video. Super clear.

[@ArjanCodes]

Glad you liked it Alvaro!

[@letsaram]

I love how wisely you avoid all the issues I've had with other peoples code.

[@antoniopena1183]

Very straightforward and nice way of explaining how it all works.

[@ldebrotb09]

Thank you Arjan! Your videos about how to make more of Python (with built-in functions), write better and cleaner code, etc. motivate me in trying to become more Pythonian.

[@ArjanCodes]

Glad to hear they’re helpful to you, Lucien!

[@its_murwayi]

This guy is awesome . The stuff i pick from you everyday is priceless. Got people at work thinking am a Python god

[@martindu9083]

good video, for sort , dataclass will use all attributes by order for checking, so sort_index is not mandatory, its effected just because its the first one

[@niveshsanghvi9066]

Nice video Arjan ! Looks very useful

[@talhaamir9023]

I loved the start of the video :) This channel deserves a million subs,the only channel most quality content :)

[@kruceo]

Clearly demonstrated. Earned my “like and subscribe”! Looking forward to checking out your other tutorials/content.

[@ArjanCodes]

Thank you Marcel - glad you liked the content!

[@sf-spark129]

I've been using the conventional class in Python. This is such a great knowledge boost!!

[@estevaoyt]

Arjan, you are great inspiration, love your videos!

[@ArjanCodes]

I'm happy to hear you have been enjoying the videos!

[@qrubmeeaz]

Best Python videos in the known universe!!

[@ArjanCodes]

Thank you so much!

[@rupeshchoudhary9237]

Great job. I love you explaining style.

[@ArjanCodes]

Glad you enjoyed it!

[@Xaminn]

Damn. This information is going to save me years of time and frustration. Thanks for this.

[@python_byte]

Just loving all of your videos man, keep up the awesome work. My focus is to watch ALL THE VIDEOS

[@ArjanCodes]

Thanks, glad you like the videos!

[@andrewiglinski148]

Dude I'm a pretty experienced developer but brand new to python as of 2 months ago... I've seen like 5 videos on dataclasses by now and this is the first one that actually showed the benefits over regular classes... after by mile long init function is finished lol

[@gedtoon6451]

I find the content of your videos are on the edge of my python knowledge. When I watch one, I learn something new, without it making my brain hurt!

[@ArjanCodes]

That's a good way to put it! Ahah, I'm glad you're enjoying the content!

[@AdityaDiwakarVex]

Video quality is insanely good for only 8K subscribers. Keep it up!

[@ArjanCodes]

Thanks, will do!

[@christopherc4526]

Just found your channel and I am glad I did. Outstanding introduction to very useful concepts. Well done

[@ArjanCodes]

Awesome, thank you!

[@gregoryfenn1462]

I really like this! It feels like modern python is much more robust and can be better self-documented and typed nowadays.

[@ArjanCodes]

You might also like Pydantic. It’s very similar but adds a few extras like data validation and nested models. It is a third-party package though.

[@patrikwiklund6154]

Arjan. I really appriciate your videos! Thank you! Really awesome

[@ArjanCodes]

My pleasure, Patrik!

[@leanbravo8856]

Why did I take so long to discover this channel? True goldmine of knowledge. Hit the bell.

[@ArjanCodes]

Thank you Lean, glad you like the content!

[@pippog88]

Hands dowm the best tutorials on Python! Thanks for what you're doing! :)

[@ArjanCodes]

Thank you so much!

[@pranavnyavanandi9710]

Long since I subscribed. 😊 This is quite the top notch content.

[@ArjanCodes]

Thank you so much!

[@thatinstant]

Wow! This video was super helpful in getting familiar with data classes! Great intro! ...Subscribed!

[@ArjanCodes]

Awesome! Thank you!

Awesome tutorial bro! I had used data classes but this is much more details that I didn’t know about. Thanks

[@ArjanCodes]

You’re welcome- glad you enjoyed it!

[@ikustudies]

you're making me rethink my entire codebase. i wish i could start over now but i'm so far. sheesh

[@PNadav183]

quick question about the __str__ representation you added, why did you use __str__ instead of __repr__? I usually choose __repr__ when it doesn't really make sense that an object be casted to a string but I still want to print it (for debugging or just to display it for some other reason) and I use __str__ when I think there is a relevant use case for a string casting. But these were my own conclusions and a convention I set for myself, is this a good practice? Is there any reason to use __repr__ over __str__ (or vice-versa)?

[@Noah-hi2up]

This is a really cool feature and definitely useful for my work! Are data classes actually implemented differently at the c level or is this just a shorthand format for accessing commonly used features?

[@joshcousins9422]

Such awesome content, this video got me to start learning python and I'm loving it! Big request though, could you do a video about Flask? Would be much appreciated!

[@ArjanCodes]

Thank you Josh - it’s on the list 😉.

[@peitlijozsef]

@@ArjanCodes I hope with Dash...

[@aadithyavarma]

@@ArjanCodes Can you compare Flask with FastAPI too? Seems like FastAPI is faster and is more pythonic in way, but I am unsure of the drawbacks of choosing FastAPI over Flask. Can you share your thoughts?

[@TueChristensenDK]

Very nice video, good explanations and well produced. When I see something like the frozen=True colliding with the __post_init then I get sad.... Coming from Java+lombok I am however, not really impressed with this dataclass annotation, but it did improve my knowledge of Python :) Keep the videos coming!

[@johnniedalesandro3269]

These are EXCELLENT videos.

[@elvistsang832]

This is amazing! I’ve been struggling with my project and this totally saved my day!

[@ArjanCodes]

Glad I could help, Elvis!

[@nardu]

"All your Data are belong to us" 🤣 +1 Arjan, love the Easter egg word portraits

[@BiGreDNoSecoMpAny]

loved Empire Earth as well xD

[@hlore7600]

Amazing! Thank you for creating this content!

[@ArjanCodes]

Glad you enjoy it!

[@GJ22]

All of your videos are still a little above my aptitude, I'm still relatively new to coding in general but I feel jumping in at the deep end can sometimes be good 👍

[@Gajet9]

I do understand that you used sort_index to showcase field types, but wouldn't it be more intuitive to define sort_index to be a property? That way we ensure it's readonly and we also ensure the sort_index updates automatically™ as the relevant fields are updated.

[@manonthedollar]

I've never been totally sold on data classes. To me, the functionality has been available forever in the form of dunder methods, @property decorators, and such. Am I being unreasonable here? Is there any sort of performance gain to data classes? Thanks for the excellent video as always!

[@ArjanCodes]

Thanks! Actually, data classes are exactly the same as regular classes. The only thing the decorator does is already add dunder methods to make the class more suitable for dealing with representing data. So it's basically a shorter version of adding dunder methods yourself. Obviously, if what the data class decorator adds doesn't fit with what you need, then it is better to define those methods yourself, there is no particular performance gain to data classes.

[@mikeciul8599]

Can you make sort_index a @property so you don't have to mess around with mutation at all?

[@justchary]

Very good! Thank you. You really have a talent to explain things

[@davidbacter5424]

Most of the programming channels show basic information with less relevant examples. I just came across this channel and let me tell you that you share the most relevant information I have ever seen on any channel. Thank you for your work, I really appreciate it!

[@glebsidorov9647]

Thanks for the class Mr :)

[@VoyivodaFTW1]

That HHKB. Typing was so fast and smooth.

[@ArjanCodes]

It's a Keychron K2. Feels great.

[@RonaldPostelmans]

Hoi Arjan. Je maakt mooie video’s met duidelijke uitleg. Kun je een praktisch voorbeeld geven waarvoor jij data classes zou gebruiken. Ik zou denken dat, je die niet nodig hebt als je bv crud operaties wilt doen naar b.v. een SQL database

[@ArjanCodes]

Hi Ronald, dankjewel! Dataclasses zijn erg handig in combinatie met Pydantic, aangezien je dan gebruik kunt maken van validatie van velden voor bijvoorbeeld APIs of database-modellen. Het is ook handig voor het representeren van een set config-waarden die je uit bijvoorbeeld een JSON file leest.

[@it_is_ni]

Another small thing: I see you using both single and double quotes. If you use a formatter (like Black) and set VSCode to Format on Save you’ll automatically get rid of these inconsistencies.

[@ArjanCodes]

In my more recent videos, I’ve started using a combination of Pylance, Pylint and Black - works really well!

[@diogosilva3152]

I have been programming in Python for quite some time now, and I had no idea of this functionality. Thanks :p

[@hoshiataru]

I tried making a playing card dataclass but since the comparison is dependent on the tuple of all values I had to override the comparison operators or "Ace of Hearts is > Ace of Diamonds (H > D)". I'm really new to Python (and programming), I thought dataclass would be good for playing card class as it's just a data holder anyway but if I ended up implementing my own sorting is it still worth using? Overhead? It's such a simple use case maybe I'm over complicating things? I think my only benefit was the repr, str, and the init having done for me.

[@PanduPoluan]

Maybe check also the attr.s package.

[@zolika154]

You’re going to be a channel with many subs ! Mark my words.

[@nowyouknow2249]

You are my python role model

[@ShanilPanara]

Loved this!

[@PanduPoluan]

Ahahahah, the opening where you're presenting dataclasses as if they're a sponsor, that's hilarious 😂

[@ArjanCodes]

Thank you Pandu, glad you liked the video!

[@Orionrobots]

Could that sort order field be made as a python property? Do we get some shortcuts around using slots for packing these in memory when in large arrays?

[@crosby3108]

This was amazing thanks for going into so much detail

[@ArjanCodes]

Thanks - glad you liked it!

[@debakarr]

That "ALL YOUR DATA BELONG TO US" in the background was funny. Nice quality content btw :)

[@ArjanCodes]

Thank you!

[@Hirnlappen]

What happens if, for example, self.sort_index = self.strength in __post_init__, we instantiate a Geralt at some point in the code but change his strength to something else later? Does sort_index somehow get updated automatically?

[@sergiopovoli4332]

Thank you sir for this video! It was very helpfull for me.

[@retrofutur1st]

10/10 video, subscribed and liked 😀

[@ArjanCodes]

Thank you, glad you liked it!

[@sengatenga8552]

Hi Arjan, you have really great videos and great code. Can you do any video on database connection to python as OOP? Would love to see how you do it. Keep up the good work!

[@ArjanCodes]

Thanks Senga, happy you’re enjoying the content! Thanks for the suggestions, I've put it on the list.

[@yonlehman]

I love your presentation. Keep it up. Im much less impressed with Python. Yes its powerful, but in my opinion the language grows in a very non obvious way. It starts with the @ notation to introduce what would probably have been a pure language feature (as jn class/struct) had they thought of it originally. Then towards the end you had to add weird, less readable notation such as setting attributes to overcome the weakness of the original extention. To an extent this is typical of the modern "Agile" approach which encourages starting with trivial stuff, without doing to much conceptual design, and adding stuff as your requirements evolve. But Agile recognizes that there is a price to pay, technical debt, which it encourages you to fix. In the case of a language or infrastructure you cant do that, you're committed to backwards compatibility and similar issues, so the language structure slowly decays, becomes more complex and you lose consistency.. I'm interested in your take on these comments.

[@apachethehun]

Thanks for sharing. Love this approach. Do you think dataclasses can be used for comparing two data sets. While end of records->generate a dataclass for that row and do a comparison between each row?

[@ArjanCodes]

You’re welcome! This is certainly possible. If you have more elaborate needs, such as nested data structures or need to validate the data when you create the objects, you might want to take a look at Pydantic.

[@disko.kommando]

Great video though I am struggling to find my own personal use cases. Seems unpythonic in syntax to me?

[@matthewbailey3052]

Very useful, thanks!

[@drheaddamage]

It's funny that the main touted advantage of Python is that it's got dynamically typed variables. And now the first thing the seasoned programmer does is *hammer those variables down to be a single type to avoid issues further down the road* 😁

[@aurielklasovsky1435]

Oh my, that is a great product! I wish there was a way to pre order it though... It seems to ve impossible atm🤔

[@abrahamvivas9540]

And this is how Python get a little bit closer to Haskell... Nice!

[@YASYTU]

But then why don't we just use Haskell?

[@ayzack2361]

Nice video, man! I like your videos.

[@ArjanCodes]

Thanks! Glad you like them.

[@FRANKWHITE1996]

Great video. Thanks for sharing.

[@aleksandramilicevic1153]

Hey, could you tell me, why am I getting this error, what can be the problem. TypeError: '>' not supported between instances of 'Person' and 'Person' minute : 06:31

[@phoenix3e3]

I haven't used dataclasses yet, but this video does a good job of showing all the features of them! I am curious, can you add any methods to the dataclass that you want that can use that data to calculate something? Or are you limited to just dunder methods? If you can add your own methods than when do you stop using dataclasses and start using regular classes?

[@ArjanCodes]

You absolutely can add your own methods to dataclasses. In the end, the dataclass decorator doesn’t change the definition of what a class is in Python, it simply sets it up to better fit a concept that represents data, including ordering, initializing with values, and so on. If you don’t need any of those things, then there’s no need to use dataclasses, simply use a regular class.

[@mikelancaster8924]

Thanks, great job!

[@Newascap]

Amazing Friday start, thanks for uploading

[@ArjanCodes]

Hope you enjoyed it!

[@Newascap]

@@ArjanCodes Already on your final thoughts. Learned a new decorator and definitely will apply to my projects from now on.

[@ranaanas-cl2cj]

love ur work thanks please continue we need you

[@ArjanCodes]

Thank you so much! No worries, I will :).

[@Wachpwnski]

I already knew all this and still watched the video. You are very talented at explaining these concepts and demonstrating them. Keep up the good work!

[@ArjanCodes]

Thank you so much, John, happy you enjoyed it!

[@andrewferguson6901]

i take it that the existence of the setattr method "workaround" means that frozen variables should not be used for security purposes?

[@ArjanCodes]

I think I'll revisit dataclasses in a future video. The setattr workaround is really ugly, so I'm going to figure out a cleaner way to do this.

[@victorh.torres2713]

Thanks a lot for your explanation! Exists some uses cases when it's better not to used dataclass and better use a regular class?

[@ArjanCodes]

Thanks, glad you liked it! One example where using a regular class is better is if the class is very behavior-focused and doesn’t have many instance variables. Also, if you need a very different initializer and don’t need the other features of dataclasses, a regular class is better. Finally, you shouldn’t use a dataclass for classes that act more like interfaces in your system (e.g. abstract classes or protocol classes).

[@exoptc1650]

Can someone explain to me why the comparison at 04:20 is now True eventhough its 2 different objects? Is it because the values are now compared

[@ArjanCodes]

Exactly! This is one thing that dataclasses does: it defines a comparison dunder method for you that compares the data values (which is often what you want when you compare data).

[@fabulousfabio8228]

Thanks for the video. I just learnt something!

[@ArjanCodes]

Glad it was helpful!

[@tuxhome3686]

Great video! I learned a lot.

[@AJ-et3vf]

Awesome video! Thank you!

[@ArjanCodes]

You're welcome AJ!

[@techcode_man]

Just awesome!! Thank you

[@ArjanCodes]

You're welcome!

[@Ezechielpitau]

very clear, good length, witcher references. what's not to like? subscribed :)

[@ArjanCodes]

Welcome aboard!